Various types of drive mechanisms and aerodynamic surface support, especially the flaps of aircraft wings, are known in the state of the art.
In this sense, mechanisms of the “simple hinge” kind are used for driving aerodynamic surfaces such as, for instance, the flaps, when they are driven and moved in the perpendicular direction to the trailing edges of the wings (movement Chordwise).
When it is desirable to move the flaps in a direction parallel to the flight direction (Streamwise movement), other mechanisms are known and used such as, for instance, the “roller track”, “combined hinges”, “four-bar” mechanism, among others.
However, these already known aerodynamic surface drive mechanisms present flaws, such as the lack of robustness, localized wear and tear and high number of parts in the case of the “roller track” mechanism, impossibility of driving in a Streamwise movement when the “simple hinge” mechanism is used.
The movement of the flaps in a direction parallel to the flight direction (Streamwise movement) is often preferred because it diminishes drag compared to the movement of the flaps in a direction perpendicular to the trailing edges of the wings (Chordwise movement). However, the sweeping of the aircraft wings, required by the high speed of the modern jets, requires an aerodynamic surface drive mechanism such as flaps that enable the “Fowler” movement when the flap is driven. The “Fowler” movement is characterized by an initial horizontal movement, followed by a rotation.
Thus, further in relation to drive mechanisms already known in the state of the art, document U.S. Pat. No. 4,448,375 refers to a device for trailing flaps formed by a four-bar mechanism with the use of “swing-link” and rotary actuators to perform the “Fowler” movement when the flap is driven. The drawback of using “swing-link” in this movement lies in the increase of loads in the mechanism combination and flap panel when it is slanted on the plane transversal to the aircraft. Additionally, the “swing-link” provides a greater degree of freedom, whereby introducing more leeway in the flap mechanism, adversely affecting the robustness of the combination.
The “Layout” document published in Mechanical Design of High Lift Systems for High Aspect Ratio Swept Wings (Rudolph, P.—NASA 1998) illustrated in FIG. 1 shows a flap drive mechanism that uses, as indicated in the drawing, the principle of the “simple hinge”, with a rotary actuator and “swing-link”. Although this mechanism enables the flaps to be driven streamwise, this movement is made by way of the rotary actuator 1 fixed to the structure of the aircraft, in this case a wing, a spherical joint 2 disposed on the flap and a rod 3 acting as “swing-link” which is a rod privotable at its ends, between the mechanism and the flap, used to transfer loads exclusively in the direction parallel to the axis formed by these ends.
One objective of the present invention is to provide a robust mechanism, that is, without problematic elements such as rails or “swing-link” for driving aerodynamic surfaces moving them in a direction parallel to the flight direction (Streamwise movement).